"Best available science" is a popular phrase these days. Environmentalists use it. So do supporters of agriculture. Politicians love it. They all see it as a way to settle thorny disputes involving resources and wildlife.
Without it, they agree that resource management would become a tool of political manipulation.
But there's a problem with that. Consider the case of the polar bear, which in 2008 the U.S. Fish and Wildlife Service listed as threatened under the federal Endangered Species Act.
According to that agency, there are between 20,000 and 25,000 polar bears in 19 distinct populations, and the number of bears was increasing or stable in eight of those populations.
The agency's scientists attributed the decline in 11 polar bear populations to less sea ice, which they blamed on global warming. They did not say why the eight populations were thriving despite the alleged lack of sea ice.
The agency further theorized that, based on models developed by the International Panel on Climate Change, the amount of sea ice would drop 30 percent by the mid-21st century, further threatening the bears.
Fair enough, but then the agency's scientists took another leap of faith and attributed those changes to global warming, which in turn they theorize was caused by greenhouse gases.
This daisy chain of theories led from a cow's burp in California to the demise of a polar bear cub north of Greenland. It should be noted that Greenland was so named because when the Norwegians first arrived there it supported lots of vegetation. They even grew barley there. But that was before global warming left it covered by a sheet of ice.
Are you following all of this?
A federal judge in Washington, D.C., has ruled that science really means conjecture when applied to the Endangered Species Act. As long as a theory represents the "best available science," no further questions need be asked.
In that case, challenging the ESA listing of polar bears, Judge Emmet G. Sullivan ruled that Fish and Wildlife scientists cannot be expected to be correct or even to study further why polar bears are thriving or not thriving as long as they use the most popular theories to support their decisions.
The problem is that scientists have not found a direct cause-and-effect relationship between greenhouse gases and polar bears. This is critically important for all producers of carbon dioxide, including livestock and dairy operators -- and everyone else, for that matter. That we might be furthering the demise of polar bears with each breath is a thought worth pondering.
That's not a problem, Sullivan ruled. "It is well settled in the D.C. Circuit that (the Fish and Wildlife Service) is entitled -- and, indeed, required -- to rely on the best available science, even if that science is uncertain and even 'quite inconclusive,'" he said.
Say what? In his ruling, the judge has allowed the replacement of hard science with a gumbo of soft theories. He is saying that if the ice melts in one part of the globe causing polar bears to become threatened any and all theoretical causes should be considered.
"This court is bound to uphold the agency's determination that the polar bear is a threatened species as long as it is reasonable, regardless of whether there may be other reasonable, or even more reasonable, views," the judge wrote.
Again, say what?
The reason this is important is Fish and Wildlife Service managers now must figure how to protect polar bears. This is exceedingly difficult, since they don't know for sure what is causing their numbers to decline in some cases and increase in others.
But since the judge says that theories and conjecture can pass for "best available science," that puts everyone at risk.
And if conjecture is OK for an ESA designation, can one based on a hunch or even a wild guess be far behind?
Science is science. Not even the wishful thinking of proponents of the ESA can dispute that point.
Under the ESA -- possibly the worst federal law ever written -- we now live in the era of "best available conjecture."